1. Field of the Invention
This invention relates generally to heat exchange equipment, and more particularly to a heat exchanger for heating process gases in an intertwined dual helical, annular conduit surrounding a burner fired air chamber.
2. Comment Concerning the Related Art
Heat exchangers are well known in the art. The most common are for thermal exchange between gaseous and liquid fluids such as air and water. For example, residential forced-air and hot water heating units generally heat air with a burner, the hot air rising through heating coils which are within the air flow or water flow path of the working fluid, i.e., air or water. In a nuclear power generator, the heat exchanger is a pipe carrying the working fluid, whereby the pipe is directed through the reactor core so as to transfer heat to the working fluid through the pipe's wall. In a solar energy heating system, the heat exchanger, is again, a coiled pipe residing in a hot water tank. Water cooling is provided in automobiles by passing ambient air through a grill-work attached to a radiator storage tank through which an engine cooling fluid is circulated.
The prior art teaches the use of heat exchangers for conducting heat from one fluid to another. The present invention is such an apparatus. However, the prior art does not teach that heat may be transferred by placing two intertwined helical flow paths around a combustion and heating chamber 30 and by driving the two fluids in counter flow directions. The present invention fulfills these needs and provides further related advantages as described in the following summary.